As promised an update to the Montana 610 saga. Mr Short of Short Tronics did the evaluation and it turns out there was a damaged USB port and the USB protection circuit was burnt which necessitated a replacement board. He replaced it with a board and back cover from a 650t and it's on its way back to me now.
I know exactly how I caused the damage and it was a total bone head move on my part. As I tell my kids, we pay for our education one way or another.
I can honestly say I'm beyond impressed with the service I received from Mr Short and can wholeheartedly recommend his services in the future.